Generally there exists a variety of different stacked assemblies and structures in the context of electronics and electronic products.
The motivation behind the integration of electronics and related products may be as diverse as the related use contexts. Relatively often size savings, weight savings, cost savings, or just efficient integration of components is sought for when the resulting solution ultimately exhibits a multilayer nature. In turn, the associated use scenarios may relate to product packages or food casings, visual design of device housings, wearable electronics, personal electronic devices, displays, detectors or sensors, vehicle interiors, antennae, labels, vehicle electronics, etc. Electronics such as electronic components, ICs (integrated circuit), and conductors, may be generally provided onto a substrate element by a plurality of different techniques. For example, ready-made electronics such as various surface mount devices (SMD) may be mounted on a substrate surface that ultimately forms an inner or outer interface layer of a multilayer structure. Additionally, technologies falling under the term “printed electronics” may be applied to actually produce electronics directly to the associated substrate. The term “printed” refers in this context to various printing techniques capable of producing electronics/electrical elements, including but not limited to screen printing, flexography, and inkjet printing, through substantially additive printing process. The used substrates may be flexible and printed materials organic, which is however, not necessarily always the case.
For example, the aforementioned wearable electronics and generally wearable technology such as smart clothing fuses textiles, other wearable materials and electronic devices to make a wearer's life easier by implementing different aspects of ubiquitous computing for both private and business purposes in wearable items such as garments. Recent advancements in material technology and miniaturization have brought forward solutions that the users have only dreamed about a decade or two ago. Hard shell wearable technology such as various smart watches or generally wristop devices has been limitedly available for some time now starting from the 80's wristop calculator watches evolving into sports/fitness computers, activity monitors and most recently, various communications-enabled apparatuses approaching e.g. cell phones and tablets in terms of embedded features. Yet, few wearable smartglasses and e.g. personal security-related products have hit the markets since. Actual e-textiles or ‘smart textiles’ have also been introduced during the last few years with reference to fabrics that provided for integration with electronics, such as sensory integration. The e-textiles may incorporate both electrically conductive materials, such as conductive yarn, and insulating materials for providing the desired electrical properties to the components embedded therewithin.
FIG. 1 illustrates one typical example of a multilayer construction 100 integrating and embedding electronics. A substrate 102 has been provided with a number of electronic components 106 and conductor traces 108 between them. Conductive contact points may have been established on the substrate for at least electrically connecting the provided components 106 to traces 108 and other elements of the substrate. A further material layer 104 has been provided on top using a suitable lamination method incorporating the use of e.g. adhesives, elevated temperatures and/or pressure.
The obtained structure 100 of the shown type may, notwithstanding the many benefits it undoubtedly has in terms of integration and protection, easily turn out sub-optimum having regard to one or more other important aspects affecting its usability, certainly still depending on the particular use scenario in question.
For instance, the stacked structure 100 may eventually appear too stiff or correspondingly, too flexible, as the elasticity of the structure heavily depends on the used materials 102 and 104, the properties of which are for their part, however, typically relatively straightforwardly dictated by the characteristics of the provided components 106, conductors 108 between them and the desired functionality of the components 106 in the established structure. Indeed, the preferred electronics 106, 108 may have been originally designed to function properly only in certain conditions and to withstand only a limited manipulation, e.g. flexure, implying either absolutely necessary or at least highly advantageous environmental operation parameters. Therefore, the material properties of the surrounding, electronics-embedding materials have been selected to meet the expectations determined by the electronics. Meanwhile, from the general standpoint the resulting material characteristics have actually provided disappointing side effects as to the elasticity, tactile, optical and/or aesthetic properties of the overall construction 100, for example.